Technical Field
The present invention relates to a pneumatic tire.
Related Art
WO 2012/111589, Japanese Patent 5639461, Japanese Patent 3376342 and JP 2012-96782 A disclose a pneumatic tire having a plurality of block rows extending in a tire circumferential direction. Each block row has a plurality of blocks arranged in a row in the tire circumferential direction. However, it is not always the case with these conventional pneumatic tires that the pneumatic tire has succeeded in enhancing all of the following: drive performance, braking performance and turning performance while ensuring drain performance.
There have been proposed tires having various tread patterns for the purpose of enhancing motion performances (acceleration, braking, turning and the like) on a dry road surface (a road surface on which no rain or snow has fallen) and a snowy road surface (snowy road).
For example, on a tread surface of a tire disclosed in Japanese Patent 5528208, shallow grooves each having recessed portions (sipes) formed on a groove bottom are formed on a rib formed between two main grooves disposed adjacently to each other at predetermined intervals. With such a configuration, a ground contact area can be reduced and hence, road noises can be reduced.
In Japanese Patent 4718294, in a shoulder region, sipes are formed on a bottom of a lug groove. The sipes arranged on the groove bottom are minimally erased even when the pneumatic tire is used for a long period and hence, on-snow performance obtained by the sipes can be maintained for a long period.